# Two cars left the city for a suburb, 120 km away, at the same time. The speed of one of the cars was 20 km/hour greater than the speed of the other, and that is why it arrived at the suburb 1 hour before the other car. What is the speed of both cars.?

##### 1 Answer

Slower car:

Faster car:

#### Explanation:

Let

The time it took the faster car to reach the suburb is

Since distance

The speed of the slower car is

The speed of the faster car is

Since the faster car travelled

Now multiply both sides by

Simplify, distribute, factor, disregard, etc. Essentially, solve.

Since

We know that the speed of the slower car is

Slower car:

Faster car: